a(n) = [x^n] exp(Sum_{k>=1} sigma_n(k)*x^k/k).

A319361

a(n) = [x^n] exp(Sum_{k>=1} sigma_n(k)*x^k/k).

Terms

    a(0) =1a(1) =1a(2) =3a(3) =14a(4) =136a(5) =2411a(6) =88903a(7) =6309849a(8) =866470849a(9) =240522266760

External references